Since the 2022 invasion of Ukraine, Russian GPS interference has disrupted thousands of flights, including a Spanish military plane carrying the country’s defense minister, highlighting how easily satellite navigation can be jammed or spoofed. While new GPS III and GPS IIIF satellites and alternative position data from cellular and visual sources are in development, a parallel effort is pushing quantum navigation, which uses the quantum properties of light and atoms to create autonomous navigation systems that do not rely on satellites. US agencies such as the Defense Advanced Research Projects Agency and the Defense Innovation Unit have launched new grant programs to move these technologies from the lab into operational military vehicles.
Today’s inertial navigation, which estimates position from speed, direction, and time, suffers from compounding errors; Douglas Paul of the UK’s Hub for Quantum Enabled Precision, Navigation & Timing notes that existing specialized inertial-navigation devices might be off by 20 kilometers after 100 hours of travel, while cheap smartphone-grade sensors produce more than twice that level of uncertainty after just one hour. Companies such as Infleqtion are building quantum gyroscopes and accelerometers based on atom interferometry, in which rubidium atoms are split and recombined with lasers so that changes in phase reveal motion. Infleqtion has flight-tested pulsed-atom inertial sensors at a British military range and more recently trialed a continuous-atom system to enable uninterrupted navigation, and it also fields an optical atomic clock called Tiqker that, according to project lead Max Perez, will lose one second every 2 million years or so and has already been demonstrated on UK flights, US Army ground vehicles in New Mexico, and a drone submarine.
Beyond inertial systems, researchers are exploiting Earth’s magnetic and gravitational anomalies as navigation aids by comparing local field measurements to detailed maps, with Allison Kealy’s team at Swinburne University using nitrogen-vacancy diamonds whose quantum states respond sensitively to magnetic fields to infer position. Australian firm Q-CTRL is tackling the problem of deploying delicate quantum sensors in noisy real-world environments, where metal airframes and wiring can produce 100 to 1,000 times more noise than signal, by applying machine learning to filter data from its magnetic navigation system tested on a specially outfitted Cessna, achieving what CEO Michael Biercuk describes as tracking up to 94 times as accurately as a strategic-grade conventional inertial navigation system. Q-CTRL’s “software-ruggedized” mag-nav product Ironstone Opal has secured two Defense Advanced Research Projects Agency contracts and is being trialed with Northrop Grumman, Lockheed Martin, and Airbus, as the company works to shrink and toughen the hardware for deployment next year. While modern GPS III satellites add new civilian L1C and L5 signals and military upgrades such as M-code and Regional Military Protection promise stronger, more resilient coverage, and low Earth orbit constellations like Starlink offer faster, harder-to-jam signals, navigation experts such as Delft University’s Lotfi Massarweh argue that the future lies in sensor fusion across satellites and quantum sensors. If quantum devices can remain stable over one week rather than tens of minutes, he says the resulting systems would be a complete game changer for vehicles from airliners to submarines operating in GPS-denied environments.
